In inking mechanisms for printing presses, inkbox rollers are employed to bring the ink from an ink reservoir. To regulate the amount of ink transferred, it is necessary to adjust the drive turning speed of the inkbox roller. Ordinarily the inkbox roller is driven stepwise, since for each case only ink strips of small width are to be transferred from the inkbox to the inking mechanism. Corresponding, in the regulation of the turning speed of the inkbox roller, a fundamental adjustment is necessary of the step width. As one standard for the drive transfer, there has been developed an adjustable slide box guidance mechanism which is connected with an oscillating drive that is derived from the plate cylinder of the printing press.
A device of the above-mentioned type is described in German Pat. No. 1,000,400 as shifting gear for the inkbox roller of a printing press. There a freewheeling ratchet gear is journalled on the drive pin of the inkbox roller. To the drive pin of the freewheeling ratchet gear there is fastened a slide block that grips into a slide guide member which is arranged swingable on its one end on a pusher adjustably carried on the machine frame. In the slide guide member there engages a second slide block which is connected with a drive shaft derived from the machine drive as crank pin. For the adjustment of the pusher there is provided a setting spindle connected with the machine frame. By turning the setting spindle, the pusher and also the pivot axis of the slide block guide is shifted on the freewheeling ratchet relative to the slide block. Thus, the effective swinging path of the slide block guide on the freewheeling ratchet is made adjustable from 0 to a maximal swinging path. Because of the low pitch of the screw spindle thread, the shifting of this drive is, however, relatively expensive. In other words, from the least-positive ink ductor path to the maximal ink ductor path, a large number of revolutions of the setting spindle need to be carried out. Nevertheless, the extreme fineness of the possible setting provided by this arrangement is not at all necessary in actual practice.